Impact of the COVID-19 epidemic on cancer burden and cancer care in Slovenia: a follow-up study

The impact of the COVID-19 pandemic on incidence gap in screen-detectable cancers: a cohort study in Greater Poland, Poland

Background

The global COVID-19 pandemic has had a significant impact on healthcare systems. This study aimed to assess the incidence gap in screening-detectable cancers in the Greater Poland (Poland) in 2020.

Materials and methods

Data on breast, cervix uteri, and colorectal cancer cases diagnosed from 2010 to 2020 were obtained from the regional cancer registry. Standardized incidence ratios (SIR) and incidence rate differences (IRD) were calculated to estimate the change in incident cancer cases during the pandemic. The number of observed cases was extracted from the registry database. Simple linear regression analysis was used to predict the expected number of incident cancer cases in 2020 and the age-standardized incidence rate based on registry data from the preceding ten years (2010-2019).

Results

In 2020, the registered number of incident female breast cancer cases decreased by 12% [SIR 0.88, 95% confidence interval (CI): 0.88-0.92, observed: 1,848, expected: 2,101], resulting in an IRD of -6.3 per 100 K. The number of registered cervical cancers decreased by 15% (SIR 0.85, 95% CI: 0.73-0.98, observed: 181, expected: 213), with an IRD of -0.8 per 100 K. For colorectal cancer, there was a 16% decrease in new cases among females (SIR 0.84, 95% CI: 0.78-0.90) and a 15% decrease among males (SIR 0.85, 95% CI: 0.80-0.91), resulting in IRDs of -3.04 and -5.29 per 100K, respectively.

Conclusions

The COVID-19 pandemic led to a significant, 15% decrease in newly diagnosed screening-detectable cancer cases in 2020. Further studies are needed to investigate the impact of delayed cancer diagnoses on stage at diagnosis and survival rates.

Decrease in the number of new cancer diagnoses during the first year of the COVID-19 pandemic - cohort study of 3.5 million individuals in western Poland

Introduction

The COVID-19 pandemic has considerably affected healthcare systems worldwide and is expected to influence cancer incidence, mortality, stage at diagnosis, and survival. This study aimed to assess COVID-19-related changes in cancer incidence observed in 2020 in the Greater Poland region.

Materials and methods

Data from the Greater Poland Cancer Registry on cancer patients diagnosed between 2010 and 2020 were analysed. To quantify the change in the number of incident cancer cases during the COVID-19 pandemic, we calculated the standardized incidence ratio (SIR) and the incidence rate difference (IRD) to assume the pandemic-attributable gap in cancer incidence.

Results

In 2020, in Greater Poland, the expected number of new cancer cases was 18 154 (9 226 among males and 8 927 among females), while the observed number was 14 770 (7 336 among males and 7 434 among females). The registered number of cancer cases decreased in 2020 by 20% (SIR 0·80, 95% CI 0·78 to 0·81) and 17% (SIR 0·83, 95% CI 0·81 to 0·85) in males and females, respectively. Among men, the most significant difference was reported for myeloma (SIR 0·59, 95% CI 0·45 to 0·77), among women for bone cancer (SIR 0·47, 95% CI 0·20 to 0·93). In females the observed incidence was higher than expected for cancer of an unspecified site (SIR 1·19, 95% CI 1·01 to 1·38). In our study, the decrease in new cancer cases was greater in males than in females.

Discussion

The observed incidence was affected in most cancer sites, with the most significant deviation from the expected number in the case of myeloma. An increase in the observed incidence was reported only in women diagnosed with cancer of an unspecified site, which might reflect shortages in access to oncological diagnostics.